It's not just a "color"; it's a bit more complex than that. There are four colors in the burst and the varnish is ambered slightly to warm it up a bit. Then there's the blending, which is a bit different for each bass, because there's a human spraying it.
“I say in speeches that a plausible mission of artists is to make people appreciate being alive at least a little bit. I am then asked if I know of any artists who pulled that off. I reply, 'The Beatles did.”
― Kurt Vonnegut